Method and apparatus for modifying lock keys

ABSTRACT

Method and apparatus for modifying a key adapted for moving the bolt of a lock. The modification destroys the capability of the key from being used as a pattern by heretofore means to make further lock-operable duplicate keys, but which modification does not hinder the functional capability of the key for moving the lock bolt for which it was initially designed. The method and apparatus provides for alteration of the reference surface of the key relative to the pin grooves.

United States Patent 1191 Comtois METHOD AND APPARATUS FOR MODIFYING LOCK KEYS [22] Filed: June 15, 1973 [21] Appl. No.: 370,350

52 us. c1. 76/110, 29/76 c 2.469027 5/1949 Beisscr 90/1305 3,440,906 4/1969 Allen 76/1 10 FORElGN PATENTS OR APPLICATIONS l,209.847 H1966 Germany 76/110 Primary Examiner-Harrison L. Hinson Attorney, Agent, or FirmSchatzel & Humrick [57] ABSTRACT Method and apparatus for modifying a key adapted 51 1111 C1 B2lk 13/00 B23d 67/00 for Ming of a lock The mdificatiO" [58] Field of Search 76/110 29/763 90113.05 stmys the capability key from bemg used as a v pattern by heretofore means to make further lock- [56] References Cited operable duplicate keys, but which modification does not hinder the functional capability of the key for UNITED STATES ATENTS moving the lock belt for which it was initially designed The method and apparatus provides for alteration of the reference surface of the key relative to the 2:038:949 4/1936 pm grooves 2,176,106 10/1939 Segal 90/1305 5 Claims, 7 Drawing Figures PRIOR ART PATENTEBUBI 1 51914 SHE! 2 OF 2 Fig-4 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lock and key security apparatus and more particularly to modification of keys to render the keys unfit for use in making operable duplicate keys.

2. Nature of the Prior Art Locks carrying bolts operable by mechanical keys have been widely used for securing buildings, boxes, containers, vehicles, etc., from unauthorized persons for many years. In theory, only authorized persons will have access to possession of lock operable keys and therefore all unauthorized persons are automatically excluded from being capable of operating the lock. However, in utilizing lock and key arrangements it has become a widespread practice to make duplicate copies of the operable keys. For example, it is common practice for commercial business establishments to install key duplicating machines and then offer the service of making duplicate keys to patrons producing a key and willing to pay a nominal fee. These key duplicating machines are generally very easy to operate such that semi-skilled and unskilled operators are capable of producing duplicate keys from a master pattern. As a result thereof, frequently duplicate keys get in the possession of unauthorized personnel thereby destroying the intended function of the lock and key.

In making duplicate keys from a master pattern using standard key duplicating machines, an operator places the master pattern key to be duplicated and a blank key in the duplicating machine. The blank key generally includes a longitudinal reference surface, a stop surface and longitudinal slots matching and coinciding with those of the master pattern key to'be duplicated. The key to be duplicated may be the original first generation master key or a second generation dupli SUMMARY or THE PRESENT INVENTION The present invention provides a method and apparatus for modifying a key such that though the modified key may be utilized for actuation of the intended lock, its use as a master pattern keyfor generating operable duplicate keys is'destroyed. Any duplicate key generated from the r'nodifiedkey utilizing standard key duplicating machines will be-rendered inoperable for operating the intended lock. Thus, the person having control of the master-maintains control over the operable duplicate keys merely by modifying the authorized issued duplicate keys to' render them undesirable for further duplication. v i

In an exemplary method, a key, upon being duplicated from a master key is modified such that the common reference plane is distorted thereby altering the reference distances of the reference plane to the longitudinal grooves of the key while retaining the reference of the longitudinal grooves to the tumbler engaging edge of the key. Thus, if the modified-duplicated key is utilized for generating another duplicate key by available key duplicating machines, the duplicate of the modified-duplicated key will be such that the spatial relationship between the tumbler engaging edge of the longitudinal grooves will be altered relative to that of an operable master key and the modified-duplicated key. As a result thereof, the duplicate of the modifled-duplicated key is not functional to operate the lock bolt. Accordingly, the holder of the master key may retain control of the number of and authorized possession of operable duplicate keys merely by modifying each authorized operable duplicate key prior to surrendering possession of the key.

Other embodiments and advantages "will be in part evident 'to those skilled in the art and in part pointed out hereinafter in the following description taken in connection with the accompanying drawings wherein there is shown by way of illustration and not of limitation, preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B illustrate a sideand end view, respectively, of a standard master key for operating the bolt of a lock;

FIGS. 2A and 2B illustrate a side and end view, respectively, of a modified-duplicate of the key of FIGS. 1A and 1B;

FIG. 3 illustrates a side view of a duplicate key generated from the modified-duplicate key of FIGS. 2A and 2B which exemplifies that said modifiedduplicate is of a different pattern than'the operable master or modified-duplicate;

FIG. 4 is a perspective view of a machine apparatus for modifying a key according to the present invention; and

FIG. 5 is a top view of a portion of the apparatus of FIG. 4 illustrating the interaction of the cutting wheel to the key as the key is being modified.

DETAILED DESCRIPTION OF THE PREFERRED.

. EMBODIMENT In this description, reference will first be made to a brief explanation of keys and the measures presently used for duplication of keys. Then, there will be a discussion relating to the present method for modifying the duplicate key to destroy its use as a master and apparatus for carrying out the modification.

FIGS. lAand 18 respectively illustrate a standard master" key 10 commonly used for operating a bolt of a lock. The key 10 carries ahead section 12 and a barrel section, 14. The head section 12 may be grasped by the hand of an individual for manual manipulation to insert the barrel section 14 in the key slot of a lock and to turn the barrel section 14 within the lock. The

guide for making duplicate copies of the key from coinciding blank" keys by presently available keyduplicating machines and techniques. A terminal stop 18 is provided near one terminal endof the barrel to control the distance the key can be inserted within a lock slot.

A plurality of horizontal grooves 20 and ridges 21 are machined longitudinally along the key barrel to match the alignment of the key within the lock relative to alignment bosses and valleys within the lock. ln manufacturing the key for operating a specific lock, the pattern of the grooves and ridges 21 are set relative to the reference surface 16. Generally, a large number of locks of a particular style and model are manufactured wherein the pattern of the grooves, ridges and reference planes are the same. Then each lock carries a unique tumbler pattern such that only the teeth of the key need be different in order to render keys of nonconforming teeth pattern inoperable for locks other than the one intended.

The other longitudinal edge of the key barrel 20 opposite the reference surface 16 is jagged such that a unique teeth pattern and number of teeth 22 are provided. The pattern and number of teeth 22 of the key are provided to correlate with the pattern of the tumblers within a specific lock in order to entitle the key to manipulate the specific tumbler arrangement within the lock. In manufacturing locks and keys, though the grooves, ridges and reference plane of a large number of keys may be the same, the teeth are of a different pattern so that the key is only functional for operating a specific lock. The number of teeth, their positioning and depth of cut are all of prime importance in making the key pattern for a specific lock. Generally the lock manufacturer provides the purchaser with one or two operable keys with the lock. These keys are hereinafter referred to as the master keys. To permit the making of duplicate keys capable of operating the same lock, the key manufacturer generally manufactures a large number of blank" keys having no teeth but which have a similar groove-ridge pattern, barrel length and horizontal reference plane to one another. To this extent, the blank keys coincide with all the master keys of locksof a particular style or model. These blank keys are then readily commercially distributed to key duplicating establishments which also possess key duplicating'machines. The key duplicating establishment then possesses the capabilityof generating operable duplicates from the blanks. In generating a duplicate from a blank, the master key is positioned in the key duplicating machine in a precise manner. Simultaneously, the blank is positioned in the duplicating machine such that the ref erence plane, grooves and ridges of the blank key coincide with those of the master key. Then the teeth pat tern of the master key is traced and the machine simultaneously cuts a coinciding teeth pattern in the blank. Thus, the generated key, hereinafter referred to as the second generation key, is also functional to operate the lock. Heretofore, the second generation key could also beutilized as a substitute master" key suchthat further duplicates could be generated from it using similar key duplicating machines.

FIGS. 2A and 2B illustrate a modified second generation key referred to by the general reference character 30. The key 30 is operable to operate the intended lock, but is modified suchthat if used as'a substitute master key to generate another generation of duplicate I keys, the subsequent generations of keys will not be functional to operate the samelock as the master. The configuration of the modified second generation key 30' is modified from that of the key 10 by reshaping the reference surface 16 to provide a reference surface 32 horizontally along the barrel 14 of a different configuration from that of the reference plane 16. The configuration of the remaining parts of the key 30 are duplicates of that of the key' 10 and carry the same reference numeral-distinguished by a prime designation.

The reconfigurated reference plane 32 is shaped so as to remove a portion of the barrel material of the key and alter the vertical distance from the grooves to the plane 32 from the terminal end of the barrel 14' to the vertical stop 18'. As indicated in FIG. 1A, this vertical distance on the master, represented as A, is greater than the maximum vertical distance A as indicated in FIG. 2A. It may further be noted that the reconfigured reference plane 32 on the modified second generation key 30 is shaped to carry a peak 34. The peak 34 functions as a fulcrum point such that when the key 30 is placed in a key duplicating machine, not only is the maximum vertical distance A' less than A, but the key 30 will also tend to pivot somewhat about the fulcrum point 34 thereby hindering the opportunity of providing exact parallel alignment of the grooves of the key 30 with those of the blank key using standard key duplicating machines and techniques. Thus, using standard key duplicating techniques and the modified key 30 as a master to generate a third generation key from a blank, will provide a third generation key which is-not functional to operate the same lock as operable by the master key 10 or modified second generation duplicate key 30. The teeth of the third generation key will be deeper cut in the barrel relative to the longitudinal grooves due to the removal of material all along the reference plane 16. The increase in depth of cut, even assuming that the key 30 when placed in the duplicating machine does not pivot, will be deeper by the amount A minus A. If the key 30 pivots above the fulcrum point 34 when it is placed in the key duplicating machine, some of the teeth will be deeper by an amount greater than A minus A and some less depending on'the amount of pivot. Furthermore, due to the pivoting about the fulcrum point 34, the teeth will also be off horizontal alignment relative to that of the mas ter key 10 and modifiedsecond generation key 30. To further illustrate, a third generation key 40 generated from a blank and using the modified second generation key 30 as a master is depicted in FIG. 3. As illustrated, the teeth 22" in the key 40 are deeper cut in the barrel 14" and may be off line relative to the teeth of the keys 10 and 30. Thus, the key 40 will not function to operate the lock which the master key 10 and modified second generation key30 will operate. Accordingly, modifying the configuration of the reference plane of a key destroys the use of said modified key from being used to generate further operable duplicates through it does not destroy the use of that key itself for operating the intended lock. t

FIGS. 4 and 5 illustrate machineapparatus, referred to by the general reference character 50, for modifying a key and altering the key reference surface. More ex- "plicitly, the apparatus 50 may be used to take the master key 10 as shown in FIGS. 1A and 1B or a generation of the-master key and modify its configuration to appear as that of the modified second generation key 30 of FIGS. 2A and 2B. The machine apparatus 50 in cludes a cutting-reference guide sub-assembly referred to by the general reference character 51 and including a drive motor 52 supported on a base plate 53. A drive pulley 54 is-coupled to the shaft of the motor 52 and a drive belt 56 extends from the pulley 54 to a driven pulley 58 coupled to a drive shaft 60. The drive shaft 60 is supported by a bearing 62 in turn supported in an elevated position 'over the base 53 by a stationary mount column 64. The opposite terminal end of the shaft 60 is engaged to a cutting wheel 66 having a pointed cutting edge 68. The motor 52 drives the wheel 66 about the axis of the wheel such'that the cutting edge 68 establishes a cutting plane. The cutting wheel 66 is partially enclosed by a safety shield 69.

A steel horizontal-depth guide bar 70 is supported at one end in an elevated position relative to the base 53 by a vertical support column 72. The support column 72 has a flat, front planar surface 74 flush with the guide bar 70 which projects laterally therefrom and laterally relative to the cutting plane established by the cutting wheel 66. The guide bar 70 extends beneath and beyond the periphery of the cutting wheel 66. A portion of the guide bar 70 carries a pair of inclined machined indentations 76 and 78 with a ledge 80 intermediate to establish a guide format of a mirror image of the desired configuration of the reference surface 32. i

A feed control carriage sub-assembly, referred to by the general reference character 90 is provided for engaging the key to be modified in an oriented position relative to guide bar 70 and cutting wheel 66. The subassembly 90 further provides for feeding the secured key past the cutting edge 68 in a controlled path responsive to the contour of the machined indentations 76-and 78 of the guide bar 70. The feed control subassembly 90 includes a guide rail 92 supported above the base plate 53 by a pair of laterally spaced support columns 94 and 96 and aligned along a longitudinal axis parallel to the longitudinal axis of the guide bar 70. A feed arm 98 with a boss 100 having a sleeve 102 is engaged about and co-axial with the guide rail 92. The sleeve 102 is adapted to-permit the feed arm 98 to slide laterally relative to the cutting plane of the wheel 66 along the guide rail 92 and also to be pivoted about the axis of the rail 92. A support column 104 is engaged justable cut-depth pin 120 extends laterally through the column beneath the boss 106. A terminal end 122 of the pin 120 is in alignment with the cut depth guide arm 70 so as to contact the reference surfaces 76 and 78 when the column 104 is pivoted forward towards the sub-assembly 51. The interengagement of the tip of the pin 120 and surfaces 76 and 78 establish the closest distance, the jaws of the clamp can approach the cutting edge 68 of the wheel 66 within the cutting plane. Thus, the guide bar 70 with the inclinations 76 and 78 and ledge 80 provide a guide track means for guiding the spatial relationship of the securing jaws laterally relative to, the cutting plane and the axis of the guide rail 92 as the column 104 is urged along the rail 92. The pin 120 may be adjusted by loosening a lock nut 124 and then adjusting the degree of projection of the pin 120 from the column 104. Once aligned and the operator .is ready to machine the key, the assembly 90 is pivoted such that the tip 122 of the pin 120 engages the surface of'the guide member 70; The column '104 may then'be slid laterally along the guide rail 92 such that the engaged key passes and intersects with the area of .the cutting edge 68 of the cutting wheel 66. A feed handle 118, adapted for grasping in the hand of the operator, is engaged to and projects from the back side of the boss 106. Thus, during operation, the operator may sicutting edge 68 of the cutting tool 66to remove portions of the reference surface material of the key to generate the modified second generation key 30. FIG.

normally to the boss 100 and extends to an elevated pothreaded tap 114 projecting within the boss 106. Clamp member 110 forms a horizontal flat jaw 116 alignedwith and parallel to the jaw 109. A key may be positioned and secured intermediate the jaws 109 and 116 with the reference surfacefacing the cutting-reference guide assembly 51 with the key being'supported in a horizontal plane normal tothe cutting plane of the; wheel 106.v Once positioned,ithe key may be firmly locked in position intermediate said jaws by tightening the tie-down arm 112. Loosening of the arm 112 permits the operator to easily insert, adjust or remove the key.

The feed-control carriage assembly 90 pivots about the guide rail 92 such that the key engaging jaws 109 and 116 may be laterally pivoted toward or away from the cutting edge 68 of the wheel 66 to control the cutting of the key about its reference plane surface. An ad- 5 illustrates a top view of the apparatus during operation with the key partially modified.

In positioning keys "intermediate the jaws 109 and 116, it is desirable to position them so as to assure that the resultantmodified key will be of the intended shape and pattern conforming to the pattern of 'the bar 70. The orientation and position of the key within the jaws 109 and 116 is of importance in establishing the final modified shape. Accordingly, a key orientation member is positioned about the top edge of the column 72. The orientation member 130 carries a vertical reference surface 132 with a flat horizontal lip 134 extending at right angles therefrom. The member 130 further establishes an end reference surface 135 at right angles to the vertical surface 132 and lip 134. The

member 130 is hinged to the column 72 by means of a Thus,-when a key is initially placed intermediate the jaws 109 and 116 of the feed-control assembly 90, orientation member 130 is positioned in its furtherest counter-clockwise direction position about the pin 116.

With the arm 112 loosened, the key to be modified is 7 then positioned intermediate the clamp jaws 109and 116 of the feed-control assembly 90 and in contact with the horizontal reference surface 134. The reference plane surface of the key is then urged in abutment with the vertical reference surface 132 of the orientation member, 110. The terminal stop 18 of the key is aligned in abutment with the end reference surface 135. Once the key is aligned, the turn arm 112 is tightened to lock the key in place intermediate the jaws 109 and 116. The operator may then flip the member 130 clockwise (illustrated in FIG. to permitthe handle 12 of the key to clear the member 130 without interference.

After the key is oriented and secured in place and the member 130 cleared, the operator starts the motor 50. The operator then slowly urges the handle 118 laterally parallel to the axis of the guide track 92 and towards the sub-assembly 51 such that the column 104 slides along the guide track and the tip 122 of the pin is in constant engagement with the surfaces of the guide arm 70. As the tip 122 follows the contour of the surface of the guide 70, the cutting wheel 66 simultaneously cuts away material from the key to duplicate the mirror pattern of the guide 70 along the back reference surface of the key. FIG. 5 illustrates the relative position of the key and sub-assemblies 51 and 90 with the machining operation partially completed. When the boss 100 makes contact with the column 96, the cutting edge 68 of the wheel is adjacent to the terminal stop 18 of the key; This completes the modification of the key. The column 104 may then be pivoted counter-clockwise, the arm 112 loosened and the modified duplicate key removed from intermediate the jaws 109 and 116.

While for the sake of clearness and in order to disclose the invention so that the same can be readily understood, specific embodiments have been described and illustrated, it is to be understood that the present invention is not limited to the specific means disclosed. It may be embodied in other-ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and all changes as come within the scope of the following claims are to be considered as part of the invention.

I claim:

1. Machine apparatus for modifying the barrel of a key such that the key remains functionally operable to operate an intended lock but is not compatible for making subsequent duplicate keys capable of operating the same lock, the apparatus comprising, in combinasecuring means for engaging and securing a key to be modified with the reference planar surface of the barrel facing the cutting path of the cutting tool,

said securing means being movable relative to the cutting path along a first lateral path which first lateral path intersects with the plane of the cutting path of the cutting tool such that as the securing means traverses along the first lateral path, the reference planar surface of the barrel intersects'the cutting plane;

first guide track means engaged to said securing means for guiding'said securing means along the first lateral path;

second guide track means supported over the base member for guiding said securing means laterally relative to the cutting path of the cutting tool and laterally relative to the first lateral path to control the depth of cut of the cutting tool in the barrel of the secured key as said securing means traverses along the first lateral path; and

a key alignment member supported laterally relative to said securing means to align said key within said securing means, the key alignment member including a reference surface for aligning the horizontal reference plane surface of the key relative to the securing means prior to said key being secured in said securing means.

2. The machine of claim 1 wherein the securing means includes a carriage engaged to a first track extending along said first path, said carriage including a pivotable arm pivotable about the axis of said first path and laterally relative to the first path and to the cutting path of the cutting tool; and further including depth-guide means supported over the base member and laterally relative to saidfirst path to guide the pivotable position of carriage laterally relative to the cutting path of the cutting tool.

3. The machine of claim 2 wherein the depth-guide means includes a horizontal guide bar projecting laterally from the plane of the cutting tool, a guide pin extending intermediate the carriage and the guide bar, the length of said guide pin establishing the minimal spacing between the carriage and guide bar as the carriage traverses along said first path, and in which the key alignment member is supported adjacent said guide bar for aligning the horizontal reference surface of the key relative to the guide bar prior to said key being secured in said securing means.

4. The machineof claim 3 wherein the depth-guide bar has various depths such that as the carriage traverses along said first path the minimal spacing between the carriage and the guide bar varies dependent upon the position of the carriage along the first path. 5.The machine of claim 4 wherein the key alignment member aligns said keysuch that at least a portion of the'key intersects with the cutting path of the cutting tool along the entire length of the barrel of the key.- 

1. Machine apparatus for modifying the barrel of a key such that the key remains functionally operable to operate an intended lock but is not compatible for making subsequent duplicate keys capable of operating the same lock, the apparatus comprising, in combination: a base support member; a cutting tool having a cutting edge, said tool being supported over the base member; drive means engaged to the cutting tool for driving the cutting tool with the cutting edge driven along a cutting path within a cutting plane; securing means for engaging and securing a key to be modified with the reference planar surface of the barrel facing the cutting path of the cutting tool, said securing means being movable relative to the cutting path along a first lateral path which first lateral path intersects with the plane of the cutting path of the cutting tool such that as the securing means traverses along the first lateral path, the reference planar surface of the barrel intersects the cutting plane; first guide track means engaged to said securing means for guiding said securing means along the first lateral path; second guide track means supported over the base member for guiding said securing means laterally relative to the cutting path of the cutting tool and laterally relative to the first lateral path to control the depth of cut of the cutting tool in the barrel of the secured key as said securing means traverses along the first lateral path; and a key alignment member supported laterally relative to said securing means to align said key within said securing means, the key alignment member including a reference surface for aligning the horizontal reference plane surface of the key relative to the securing means prior to said key being secured in said securing means.
 2. The machine of claim 1 wherein the securing means includes a carriage engaged to a first track extending along said first path, said carriage including a pivotable arm pivotable about the axis of said first path and laterally relative to the first path and to the cutting path of the cutting tool; and further including depth-guide means supported over the base member and laterally relative to said first path to guide the pivotable position of carriage laterally relative to the cutting path of the cutting tool.
 3. The machine of claim 2 wherein the depth-guide means includes a horizontal guide bar projecting laterally from the plane of the cutting tool, a guide pin extending intermediate the carriage and the guide bar, the length of said guide pin establishing the minimal spacing between the carriage and guide bar as the carriage traverses along said first path, and in which the key alignment member is supported adjacent said guide bar for aligning the horizontal reference surface of the key relative to the guide bar prior to said key being secured in said securing means.
 4. The machine of claim 3 wherein the depth-guide bar has various depths such that as the carriage traverses along said first path the minimal spacing between the carriage and the guide bar varies dependent upon the position of the carriage along the first path.
 5. The machine of claim 4 wherein the key alignment member aligns said key such that at least a portion of the key intersects with the cutting path of the cutting tool along the entire length of the barrel of the key. 